English

Write True Or False : No New Substance is Formed During a Chemical Reaction - Chemistry

Advertisements
Advertisements

Question

Write true or false  :
No new substance is formed during a chemical reaction.

Options

  • True

  • False

MCQ
True or False

Solution

False

shaalaa.com
  Is there an error in this question or solution?
Chapter 5: Language of Chemistry - Objective type questions

APPEARS IN

Selina Concise Chemistry [English] Class 7 ICSE
Chapter 5 Language of Chemistry
Objective type questions | Q 2.1

RELATED QUESTIONS

FILL IN THE BLANK

Negatively charged ions are called ..........


TRUE \ FALSE

Weak electrolytes dissociate partially in their aqueous or fused state.


TRUE \ FALSE

Temperature at which a liquid starts boiling is known as the boiling point of that liquid. True or false ?


 Fill in the blank

A change in which the substance can be brought back to its original state is called a _______ change.


Define chemical reaction.


Name the type of chemical reaction shown by the following equation :

Fe2O3 + 2Al → Al2O3 + 2Fe


A solution of a substance ‘X’ is used for white washing write the reaction of the substance ‘X’ named in (a) above with water.


What is a chemical reaction?


State the type of reactions for the following represent and balance the ones that are not balanced.

NaOH + HCl → NaCl + H2O


Multiple choice:

Thermal decomposition of sodium carbonate will produce


Name: Two nitrates that do not produce nitrogen dioxide on heating.


State the original colour of the following substance and colour of residue obtained after heating.

Lead nitrate


What do you observe when CO2 is passed through lime water first and then a little in excess.


Explain the term ‘chemical reaction’ with special reference to – ‘reactants’ and ‘products’.


Give reason for the following:

A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.


Give balanced equation for the following conversion affected by heat alone on the substance:

Copper nitrate to nitrogen dioxide


Complete the table given below.

Heat on  copper carbonate Test for gas evolved  

State the following reaction represent oxidation or reduction.

\[\ce{Fe++->Fe+++}\]


State the following reaction represent oxidation or reduction.

\[\ce{H->H+}\]


Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to sodium sulphite.


What happens when cane sugar is strongly heated? Mention any two changes in it.


Higher order Thinking question

A very hot glass on putting in cold water cracks. What does this change indicate?


Mention the various conditions required for a chemical reaction to occur.


Chemical change is a temporary change.


Match the following:

1. Sodium Chloride a. CaSO41/2H2O
2. Calcium sulphate dihydrate b. C2H5Oh
3. Magnesium sulphate hydrate c. CaSO4.2H2O
4. Calcium sulphate hemihydrate d. NaCl
5. Phenol e. MgSO4.H2O

A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.

Are these changes chemical in nature?


Explain how the painting of an iron gate prevents it from rusting.


Assertion (A): Cutting paper into very small pieces is an irreversible change.
Reason (R): Physical changes are always reversible.


What is thermochemical reactions?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×